UNIT 11

1	Pheromones are chemicals that animals, including insects, produce.  Plants also produce pheromones.  Studies show that flowers use pheromones to attract bees.  Pheromones play a very important role in the natural world.  For many creatures, life would not be possible without pheromones.
2	Moths are one insect that could not survive without pheromones.  Moths have poor eyesight, and most species cannot use sound to communicate.  Instead, they communicate through pheromones.  Female moths, for example, release pheromones from their legs and wings.  A male moth can identify female moth pheromones from as many as five miles away.  And because the pheromones donft wear off for several hours, male moths have enough time to find the females and breed.
3	Ants have different pheromones for different purposes.  Like moths, ants use pheromones to find each other.  They also use pheromones to find food.  When an ant finds food, it takes a piece and returns to the nest.  Along the way, it releases a trail of pheromones.  Other ants follow the trail to find the food.  If something blocks the trail, the ants look for a new way to reach the food.  When they find the shortest way, they produce a new trail of pheromones.  In this way, pheromones help ants adapt to changes in their environment.
4	When an ant is hurt or threatened, it produces an galarmh pheromone.  Other ants identify the alarm pheromone and immediately come to help.  The more serious the threat, the more alarm pheromones the ant produces.  In this way, ants can quickly organize to fight insects hundreds of times their size. 
5	Some species of ants use gtrickh pheromones to stir up trouble and confuse their enemies.  Fire ants, for example, produce pheromones near the nests of other ants.  Those ants become confused and begin to fight each other instead of attacking the fire ants.
6	Other insects use trick pheromones to imitate another species.  In some cases, this protects them from becoming the next course in another insectfs meal.  An interesting example is the Large Blue butterfly.  During its caterpillar stage, this unusual insect releases a pheromone similar to that of an ant.  If ants find a Large Blue caterpillar in the forest, they carry it home.  There, instead of eating it, they care for it \\ like a family member.  The ants do not suspect that anything is wrong, even when the caterpillar starts to eat their young!  The caterpillar doesnft leave the nest until it has safely turned into a butterfly.
7	Because of examples like these, many biologists now believe that pheromones are the true language of insects.  But pheromones are also important to plants and other animals.  Their significance in the natural world is undeniable.  Some scientists even believe that humans, like other living creatures, use pheromones to attract members of the opposite sex.  If that turns out to be true, it might be more accurate to talk about gLove at first smellh than gLove at first sight!h